This invention relates to novel chain links and to improved cable carrier chains composed of such chain links. More particularly, this invention relates to novel chain links which impart increased strength and flexibility to cable carrier chains composed of the chain links.
A cable carrier chain is a sheath designed to protect and route wires or cables in a moving application. More particularly, a cable carrier chain is an articulating sheath designed to protect and guide electrical/fiberoptic cables that are attached at one end to a fixed body and at the other end to a laterally moving body, the cable carrier chain protecting and guiding the cables while the moving body cycles throughout its full range of positions.
A cable carrier chain is composed of links that bend through a range of positions. For use in automotive and industrial applications, a robust cable carrier chain must permit repeated bilateral cycling under torsional and tension loads under various environmental conditions without the decoupling of the links that comprise the chain. An automotive cable carrier chain must also be designed to minimize noise during cycling of the chain and when the chain is at rest when it is subject to normal vehicle vibration and shock while the vehicle is in motion. Due to high volume usage of an automotive cable carrier chain, the links of the chain must be designed to aid in automated cable carrier assembly.
Cable carrier chains are known in the art. Reference is made, for example, to U.S. Pat. Nos. 4,813,224; 5,108,350; 5,201,885; 5,334,111; 5,445,569; 5,649,415; 5,839,476; 5,860,274; 5,980,409; 5,987,873; 6,065,278; 6,067,788; 6,161,372; 6,174,020; 6,190,277; 6,226,973; and U.S. Pat. No. RE 33,339.
Although cable carrier chains are known, it is continually desirable to provide cable carrier chains which exhibit improved strength, flexibility (particularly bilateral flexibility) and ease of assembly, and reduced abrasion and noise created by link-to-track contact.
A particularly desired feature not currently found in cable carrier chains is increased strength and flexibility in a small package size.
Another drawback to currently produced cable carrier chains is that they are not designed to guide cables in a bilateral motion under a torsional load. Instead, such cable carrier chains are designed for unilateral motion under tension loads only. For example, one commercially available cable carrier chain has a straight-walled (as opposed to undercut), rounded pin mating to an elliptical aperture. Mating of the elliptical aperture and the rounded pin do not allow for a large surface area to be in contact between the links. This feature only allows for half of the corner edge of the aperture to be in contact with half of the pin at one time. As a result, the chain will decouple or break when subjected to torque during bilateral motion. The use of the rounded pin also yields to decoupling because there are no flat opposing surfaces in contact with each other. Therefore, the pin can be pulled through the elliptical aperture and decoupling can occur without the pin failing. Furthermore, the mating of the straight-walled pin to an elliptical retaining wall allows for minimal flexibility before the chain links will decouple.
Another disadvantage of cable carrier chains currently produced for industrial application are disadvantageous in that they do not have an outside geometry designed to reduce noise when in use or at rest. Currently produced cable carriers have flat bottoms and do not have any provisions made to the outside geometry to reduce the contact area between the link and the track, thereby allowing extensive noise and abrasion from the track due to normal vehicle use.
A further drawback to conventional cable carrier chains is that they are currently produced for a single specific industrial application and are hand assembled. To be easily assembled in an application requiring mass production, the links of the cable carrier chain must be in their open position, allowing them to flex. Therefore, steps must be taken in the design of the chain links to prevent them from closing during the assembly process. This is currently not being done due to the lack of mass produced cable carrier chains.
Thus, a primary object of this invention is to provide chain links for use in a cable carrier chain wherein the links provide the chain with increased strength and flexibility.
A further object of this invention is to provide chain links for use in a cable carrier chain wherein the links provide the chain with increased strength and flexibility in a small package size.
A still further object of this invention is to provide chain links for use in a cable carrier chain wherein the chain links do not decouple when the chain is guiding cables in a bilateral motion under a torsional load, thus providing the chain with good bilateral flexibility.
Another object of this invention is to provide chain links for use in a cable carrier chain wherein the chain links each have an outside geometry designed to reduce abrasion and noise created by link-to-track contact while the chain is in use and while the chain is at rest.
Still another object of this invention is to provide chain links for use in cable carrier chains, wherein the links are configured so that the chains are relatively easy to assemble.
A further object of this invention is to provide a cable carrier chain composed of chain links which have the properties set forth in the preceding objects.
These and other objects are achieved in the present invention.